This invention relates, in general, to a gun and in particular to a gun with two barrels, one of which moves forward upon actuation.
Examination of U.S. Patent Literature reveals an absence of interest in guns with a delivery system containing two barrels, one of which, upon firing, is made to slide within an outer structure, like the sections of a small telescope. But a gun that is designed to produce, upon firing, the acceleration of both a projectile and also the immediate container of the projectile in the same direction and in such a manner that after moving a distance together, the immediate container of the projectile is mechanically stopped before exiting the gun, and remains a useable part of the gun while the projectile is driven forward, may have utility. This telescoping design differs from conventional guns by requiring both the bullet and an inner barrel, containing the bullet, be driven forward by the explosion of propellant. By design, an outer structure contains and directs the force of the propellant, and moves in a direction opposite that of the bullet and inner barrel (recoil).
In ballistic technology, several mechanisms exist for rearward movement of parts within a gun, as an action, which is governed by the force of recoil or the propellant gases generated by firing, however, a barrel which moves forward has elicited little interest. Though a gun with a telescoping barrel has an obvious advantage over conventional guns, in that higher projectile velocities might result from its use than is apparent judging from the outer structure barrel length; a gun with a barrel that moves with the projectile for an appreciable distance within the gun has not been pursued as a viable firearm concept, most likely because stopping a barrel that has been accelerated to a velocity which is a significant fraction of the bullet""s speed is hard to accomplish. If the barrel moves too fast, it will exit the gun; too slow and the benefits of the concept are minimal. Additionally, abrupt starting and stopping of the moveable barrel results in a stretching of the barrel""s metal, as defined by Young""s modulus, rendering the gun incapable of repeated use. These additional variables involved in perfecting a gun with a telescoping barrel seem to indicate that a weapon of such design is impractical. However, a gun that is designed to produce, upon firing, the acceleration of the projectile and also the immediate container of the projectile can be used to transfer some of the kinetic energy of the moving container of the projectile into energy that counteracts the force of the gun""s recoil, while the projectile is driven forward in the usual way. This invention is thought to be novel and different from other gun designs which utilize some of the energy of the propellant gases to counteract the force of the gun""s recoil, notably the designs of Sir Dennis Burney and subsequent battalion anti-tank guns developed in Britain in the late 1940""s, by requiring that some of the burning propellant energy be converted into kinetic energy of a moving structure within the gun, i.e. a telescoping barrel, and this energy be then used to counteract the gun""s recoil.
Adrianson, U.S. Pat. No. 855,439 simply shows a telescoping barrel for a gun, and the barrel does not telescope as the bullet is fired.
Kaufman, U.S. Pat. No. 2,852,880 simply shows a gun having a second barrel that screws into internal threads in a rear barrel portion. Again, the barrel does not telescope as the bullet is fired, and the threaded barrel is just provided for disassembly into a smaller length.
Von Frantzius, U.S. Pat. No. 2,880,543, shows a tear gas pistol, and FIGS. 6-7, with accompanying text in column 3, describes a bullet being fired from the tear gas pistol. Although the device does have a barrel that threadingly screws into the body of the pen, there is no barrel that telescopes as a bullet is fired.
Pittavino, U.S. Pat. No. 570,145 simply shows a barrel extension for a gun. The barrel does not telescope as a bullet is fired.
Hudson, U.S. Pat. No. 3,824,727 shows a small pen that fires miniature caliber projectiles. The barrel does not telescope as a projectile is fired.
Whatever the precise merits, features, and advantages of the above cited references, none of them achieves or fulfills the purposes of the telescoping barrel gun of the present invention. Accordingly, an object of the present invention is to provide a novel gun consisting of, among other things, a design including two barrels, one barrel of which moves forward within the other barrel upon actuation.
It is another object of this invention to provide a gun capable of producing projectile velocities higher than conventional guns of the same apparent barrel length, since the apparent barrel length of a telescoping barrel gun is the length of the external barrel, while the real barrel length, the distance the projectile travels while enclosed in a telescoping barrel gun is greater than the external barrel length.
A further object of this invention lies in the provision of a gun wherein the movement of the telescoping barrel is used in such a way as to counteract the recoil movement thereof responsive to the actuation of the gun.
The invention relates to a gun in which the inner barrel, which contains and directs the projectile, is made to slide forward within an outer structure or barrel when the gun is actuated. It differs from conventional gun designs by requiring both the projectile and an internal barrel to be driven forward by the explosion of propellant. When the gun is fired, the force of the detonation is contained by the breech area of an external structure and directed against the moveable parts contained within the breech area of the external structure. These parts include both the projectile and an internal barrel. The projectile resides within the internal barrel and, upon firing, is not constrained within the bore of this barrel and is driven forward, while the inner barrel also moves forward within the external structure. The motion of the inner barrel is then stopped while the projectile moves unimpeded. After the gun is fired, it must be manually reassembled to it""s pre-actuation position for continued use.
If the burning characteristics of the propellant are required to produce a high breech pressure throughout the projectile""s path in the gun, this telescoping design may be used to produce a projectile velocity which is higher than conventional guns of the same apparent barrel length since the projectile travels under the force of the propellant energy for a greater distance than the length of the outer barrel structure or the gun""s apparent length.
The gun also uses the telescoping design to allow a portion of the cartridge""s propellant energy be used to produce a significant reduction in the force of the gun""s recoil when fired. The cartridge canister and firing chamber of the gun are designed to allow some of the burning propellant gases to be channeled forward in the gun to an air space which lies between the two concentric barrels of the gun, in the early moments of cartridge detonation before the projectile and internal barrel attain an appreciable velocity. As the propellant burns and the pressure rises in the breech, a series of grooves in the firing chamber of the external barrel act as a conduit in transferring some gas from the firing chamber to this air space or forward chamber in the gun. When the pressure in the firing chamber becomes sufficient to overcome the inertia of the projectile and the internal barrel, both parts move forward. The forward motion of the internal barrel further compresses the already high-pressure gasses trapped within the forward chamber, lying between the two barrels.
This motion and also the high internal pressure of the enclosed gases, forces the gases from the gun through small voids or holes located in the distal body of the external barrel. The gases escape in a rearward direction in order to counteract the gun""s recoil. The work accomplished by the internal barrel in the forced expulsion of the gases from the external barrel appreciably reduces the velocity of the internal barrel and this slowing, together with a pressure activated ablation of the surface of the internal barrel as it moves through the external barrel, stops the internal barrel before it contacts the forward end of the external barrel. The greater part of the kinetic energy of the moving internal barrel is thought to be utilized in raising the pressure or potential energy of the gases confined in the forward chamber as the internal barrel slows and stops within the external barrel. This increase in potential energy of the confined gases significantly increases the exit velocity of the rearward directed jet streams leaving the forward chamber from the voids in the internal barrel. The compression of the gases by the moving telescoping barrel significantly helps to counter the rearward momentum of the gun produced by the exiting projectile and results in requiring less propellant gases be diverted and ejected in overcoming the gun""s recoil.
In order to accomplish the foregoing objects of this invention, the gun described consists of four main members:
A firing mechanism.
An external barrel, which contains a firing chamber, an internal barrel, and also an ablative mechanism.
An internal barrel which moves forward while containing the projectile as the gun is actuated.
An ablative mechanism that aids in slowing the internal barrel and preventing its exiting the gun.
The firing mechanism of the present invention comprises a forwardly biased longitudinal firing member or striker slidably mounted on a tubular housing which includes a removable forwardly extending external barrel portion. A transverse rod is fixedly secured to the rear end of the striker. In order to fire a cartridge chambered in the external barrel portion of the gun, the rod is manually retracted against the action of a spring and subsequent release of the rod causes this firing pin to be snapped forward, firing the cartridge.
The external barrel is an elongated metal tube closed on the proximal end by a threadably secured breech cap, which houses a breechblock that surrounds a centrally located aperture for accommodating a firing pin. The external barrel is partially closed on the distal end by reducing the bore diameter, which is preferably constant throughout the external barrel, by the inclusion of an internal metal flange.
Lying within the bore of the external barrel, forward the firing chamber, another tubular member, the internal barrel is disposed. The internal barrel is a metal cylinder open on both ends, with two annuluses fixedly secured to the outer surface of the proximal end of the barrel. The annuluses house a common rubber o-ring between them. The internal barrel is disposed within the external barrel and houses the projectile within its bore. The internal barrel abuts, with its base breech face, the cartridge canister, which is positioned within the firing chamber of the external barrel. The internal barrel is held in place within the external barrel by the frictional forces of the annuluses and o-ring, which communicate and bear against the internal surface of the external barrel. As the gun is fired, the internal barrel is free to forwardly slide within the bore of the external barrel.
The actual body or metal surface of the external barrel is altered by a design that aids in counteracting the force of the gun""s recoil. A series of grooves in the internal metal surface of the external barrel extend from the firing chamber longitudinally forward to a position adjacently forward the annuluses on the internal barrel. These grooves divert some of the burning propellant gases generated upon firing to a forward chamber within the gun. The forward chamber is an air space existing between the concentric surfaces of the two barrels, forward the annuluses of the internal barrel and rearward the flange of the external barrel. The propellant gases are pushed to the forward chamber, upon cartridge detonation, before the projectile and internal barrel move an appreciable distance within the gun. As the remaining propellant in the firing chamber burns, the pressure in the breech area of the gun increases to a point where the projectile and the internal barrel are appreciably accelerated by the impact of a semi-rigid piston, which prior to firing is positioned within the top rim of the cartridge. The semi-rigid piston is designed to prevent the propellant gases from influencing the projectile until a predetermined firing chamber pressure is established which causes the piston to rupture. When the semi-rigid piston ruptures, the propellant gases force both the piston and the projectile through the internal barrel. The forward movement of the internal barrel forces the gases, which have accumulated in the forward chamber, through voids located in the distal end of the external barrel. These voids conduct gases in the forward chamber through the metal body of the external barrel to the environment. The expelled gases are directed onto the exterior surface of the telescoping barrel as it moves forward, upon firing, by a series of metal structures or protrusions, which contain and direct the individual voids. The protrusions are positioned along the circumference of the external barrel, on the far distal area of the barrel, forward the internal flange of the external barrel. The protrusions direct the voids inward and rearward so the expelled gases push the gun in a forward direction.
A pressure sensitive ablative mechanism is also disposed in the distal portion of the forward chamber and comprises an ablative material securely affixed to an elastomer backing which functions to further slow and stop the forward motion of the internal barrel. The mechanism ablates the outer surface of the internal barrel, as it moves forward, upon firing, and the frictional forces of the ablation de-accelerate the barrel. This member is included in the gun as a means to control the speed of the internal barrel so that, after firing, the internal barrel and also the gun and its other members are relatively undamaged and capable of repeated use.
The gun is re-fired by unscrewing the breech cap from the external barrel, removing the fired case, replacing a live cartridge projectile, and repositioning the internal barrel so that its base breech face abuts the cartridge case with the projectile enclosed within the bore.
The gun described is a prototype model and used to illustrate the essential design of the invention. Since the invention relates to the initiation and projectile propagation systems of a gun, only the firing mechanism, cartridge, breech and barrel mechanisms are described. Most state of the art mechanisms involving other systems that are necessary or facilitate gun use are thought to be compatible and integratable with the mechanisms that are discussed.